Solar activity was at very low levels on 29-30 May and again on 04 June. Low levels were reached from 31 May-03 June due to flare activity from Region 2661 (N06, L=211, class/area Dao/200 on 02 June). The largest flare of the period was a C8/Sn at 02/1757 UTC. Other activity included an approximate 28 degree filament eruption centered near S11E19 observed lifting off in H-alpha imagery
beginning at 30/1300 UTC. An associated faint, narrow CME was observed off the southeast limb beginning at 30/2334 UTC.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels.

Geomagnetic field activity ranged from quiet to active levels. The period began under the continued influence of the 23 May CME. Total field reached a maximum of 17 nT at 29/0900 UTC followed by a decrease to around 8 nT by 29/1600 UTC. The Bz component deflected south to a maximum of -13 nT at 29/1230 UTC. Solar wind increased from approximately 350 km/s at the beginning of the period to a maximum of 561 km/s at 30/0940 UTC and slowly declined thereafter. The geomagnetic field responded with quiet to active conditions on 29-30 May. A return to near nominal solar wind conditions followed on 31 May-02 June. Quiet conditions were observed on 31 May and 02
June with quiet to unsettled levels observed on 01 June. At approximately 03/0615 UTC, total field, solar wind speed, density, and temperature began to increase due to the possible arrival of the 30 May CME combined with a positive polarity coronal hole high speed stream (CH HSS). Total field increased to 14 nT at 03/1125 UTC while the Bz component deflected south to -13 nT. Solar wind speed increased to near 500 km/s at 03/1825 UTC before slowly recovering
by the end of the period. The geomagnetic field responded with quiet to active levels on 03 June followed by quiet conditions on 04 June.

Forecast of Solar and Geomagnetic Activity 05 June - 01 July 2017

Solar activity is expected to be at very low to low levels from 05-12 June as Region 2661 transits across the visible disk. Very low levels are expected from 13 June-01 July.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels with high levels likely from 16-26 June due to recurrent CH HSS influence.

Geomagnetic field activity is expected to be mostly quiet with unsettled to active levels expected on 14-19 June and G1 (Minor) geomagnetic storm levels likely on 16 June due to recurrent CH HSS effects.